Candidate patients will have an initial screening visit where entry criteria must be met (see section 1.7.). Study medication will remain masked to the examiner during the entire trial. For patients assigned to the Ganforti's group, instructions for applying one drop QD (8:00 PM ± 30 minutes); for patients assigned to the Krytantek's group, application schedule will be BID (8:00 AM ± 30 minutes and 8:00 PM ± 30 minutes). Bottles will be given to the patient in a closed labeled box (with the randomization number on it), dispensed by the office assistant, and have to be returned in the same box to the assigned office personnel but never to the principal investigator or sub-investigator, in order to preserve the single-masked nature of the study. New study medication bottles will be dispensed at baseline visit, and monthly after such visit.